Insert Before Table Part In Continuation

Test for http://bugs.webkit.org/show_bug.cgi?id=15362 Safari Crashes when opening a JS TreeGrid widget.

The test sets up an inline parent with a child that is some kind of table part. The child gets broken off into a continuation and anonymous table parts get created below and/or above the table parts. Then the test tries to insert a new child into the inline, specifying the table part as the "before child". The resulting render tree should look just like it would look if the parent was a block.